The present invention relates in general to machines for simultaneously shampooing and vacuuming an area of carpet, upholstery and the like.
Heretofore, various such machines have been developed. See, for example, Finley et al, U.S. Pat. No. 4,194,262 which discloses a vacuum extraction cleaning machine adapted for coin operated applications and including an injector valve means to mix cleaning chemicals with incoming fresh water to yield the necessary cleaning solution.
Such machines are typically associated with do-it-yourself coin operated car washes and are normally positioned in an outdoor, exposed to the weather location. One common problem with such machines is the freezing of the shampoo or cleaning solution during cold weather. This problem is especially detrimental to the flexible hose which extends from the body of the machine to a remote nozzle or cleaning tool through which the shampoo or cleaning solution is sprayed.
The present inventor is aware of a shampoo/vacuum apparatus sold by Geoquip of 3141 S. Main, Ft. Worth, TX 76110 which includes means to purge liquid from the shampoo hose after usage and to heat the interior of the cabinet of the machine when temperature drops to or below 35.degree. F. The method of purging liquid from the shampoo hose is merely to blow a quantity of air through the hose to thereby blow any liquid in the hose out through the nozzle or cleaning tool on the distal end thereof.
A preliminary patentability search in Class 137, subclasses 59, 60, 61 and 62, and Class 138 subclass 32 disclosed the following patents which relate in general to car washing apparatuses or means for preventing water lines and the like from freezing but which do not relate specifically to the vacuum/shampoo apparatus of the present invention: Sanford et al, U.S. Pat. No. 2,268,086; Ligon, U.S. Pat. No. 3,037,707; Cline, U.S. Pat. No. 3,276,628; Roach, U.S. Pat. No. 3,346,191; Shelton, U.S. Pat. No. 4,360,036; Perkins, U.S. Pat. No. 4,355,652; and Anderson, U.S. Pat. No. 4,481,966. None of the above patents or apparatuses disclose or suggest the present invention.